Mixtapes' beat selections

Two friends of mine, @Marko1596 and @King_Soulo, are in the process of creating mixtapes. In terms of beat selections, can they pick up just any beat out there. For example, say if they wanted to rap over a beat like I’m On One or Can’t Get Enough or Down on Me, for example. Would they get in any legal trouble for doing so? If so, could they use beats from other mixtapes or unreleased tracks, such as beats from Stereo Sun or Temptation or Horns and Thorns?

If they release it for free, they won’t get in illegal trouble.
But come on, do you really think these record labels would care or even search the internet for this.
No, so they can use beats without any problems.

Nah I’m serious, it was asked in an other thread and everyone said they could just use the beats without any problems as long as they release it for free.
Ever heard the Dedication mixtape series from Lil Wayne? They are full with beats like New Slaves, Bugatti, FuckWithMeUKnowIGotIt etc.
Wayne can use as many beats as he would like to, because the mixtapes are for free.

As long as they don’t make any sort of money from using the beats, there can be no legal trouble. I myself am gonna take beats from online to use for a mix. You would have legal issues if you used the beats for an Ep or LP though.